An organic electroluminescent device (organic EL device) is a promising solid-state emitting type inexpensive and large full-color display device, and has been extensively developed. In general, an organic EL device includes an emitting layer and a pair of opposing electrodes holding the emitting layer therebetween. Emission is a phenomenon in which when an electric field is applied between the electrodes, electrons are injected from the cathode and holes are injected from the anode, the electrons recombine with the holes in the emitting layer to produce an excited state, and energy is emitted as light when the excited state returns to the ground state.
As compared with an inorganic light-emitting diode, conventional EL devices had a higher driving voltage, and hence had a lower luminance and a poor luminous efficiency. In addition, due to significant deterioration in properties, its practical application has not been attained yet. However, as a result of studies made on organic materials constituting an organic EL device, in an organic EL device which has been developed in recent years, the above-mentioned problems have been gradually solved.
As the organic material constituting an organic EL device, a styryl compound having an aromatic amine has been studied, for example (see Patent Document 1 or 2, for example). It is reported that an organic EL device using this styryl compound has improved luminous efficiency and prolonged lifetime.
However, there is a demand for further improvement in luminous efficiency and luminous lifetime.